• Choose a category
• All
• Classic-Fiction

"What about the third?" she asks. "It forces work centers to work at less than their maximum local efficiency. It does force subordination."

"Yes, it does," I once again agree with her. "But then . . ."

Something is still wrong.

"But then," Johnny continues my trend of thoughts, "then, if we follow all five steps, not just one, we are bound to get a better method. And that's exactly what we get."

"Wait," I stop them again. "This is important, so can we please take it a little slower? Before you show us a better method, which now I'm convinced must exist, let's see if we can spot, in JIT or assembly line, something that is not satisfactory."

"Why is that important for you?" Jim is curious.

"He just wants to find out," Johnny explains for me, "if, without our knowledge of the five focusing steps, we could have predicted that a better method exists."

"Actually," I clarify, a little embarrassed, "I haven't gone that far. I just want to check if the problems that I've identified in projects also exist in assembly lines."

Charlene looks at her watch, but Jim and Johnny encourage me to give it a try.

I don't know how.

I stand up, go to the board and slowly pick up the chalk. I look at Johnny's soldiers, all tied together now with chains. "As we said, the chains actually symbolize a restriction on the amount of inventory allowed to be accumulated locally," I say. Johnny already drew a hump of inventory in front of the X soldier. Mindlessly I add humps between each two soldiers.

"Johnny," Jim says, "can't we regard these humps as queues before machines?"

"That's exactly what they are."

"Let's not talk inventory," I impatiently say. "Let's talk time."

"Go ahead." Johnny is very patient.

"If this work center has a problem," I point arbitrarily to one of the soldiers, "then the hump represents the time that the next soldier can still work before he will have to stop. In a way," I slowly say, "these humps represent the protection a work center has. Protection against problems occurring upstream."

"You could say so," Johnny agrees. "They represent safety."

"Safety. Safety. You are right. Here is the connection to projects, don't you see?" Y-E-S! "I told you that we have to relate to inventory as representing time. In production we protect a work center with inventory, in projects we protect a step with safety time."

"I see what you mean," Jim comments, "and I agree. Still I think that there is a difference. In projects the situation is worse."

"Why?"

"Because, if there is a stoppage, inventory does not disappear. In projects, time is gone, forever."

I'm still thinking about it when Charlene comes from left field with "I have a problem with all of that. Why do we do that? Why do we try to protect the performance of each work center? I thought that we already agreed that local efficiencies don't count."

Somehow these sentences sound familiar to me. Then I recall that Ruth's complaint was "We try to protect the performance of each step." I also recall what Ruth said next. "We put in so much safety, and the project as a whole is still exposed." Does it mean here that the performance of the assembly line is exposed? Of course.

"Thank you, Charlene."

"What for?" She is still irritated by my rudeness.

"You showed me the problem with the assembly line, or JIT. We spread the protection everywhere and it's not enough, the line as a whole is exposed. In an assembly line one work center goes down and very quickly it stops the whole line."

"Of course" she says. "The only place that we want one hundred percent efficiency, the only place that needs protection, is the bottleneck. Exactly as Johnny showed us at the beginning, that's where the pile of inventory should be, right before the bottleneck, nowhere else."

I agree, but I don't see how to do it. We have to build the protection there, nowhere else. But at the same time we must prevent the spreading. It seems contradictory.

We are all looking at Johnny.

It takes some time before he realizes